The positive working photoresist composition of the present invention is coated in a thickness of 0.5-3 .mu.m on a substrate, such as semiconductor wafer, glass, ceramics or metal, by a spin or roller coating method. The coating thus obtained is heated, dried, irradiated with UV or so on via an exposure mask to print thereon a circuit pattern or the like, and then developed to provide a positive image.
Further, this positive image is used as a mask in an etching operation, and thereby a pattern is formed on the substrate. The photoresist is typically applied to production of semiconductor devices, such as IC, and circuit substrates for liquid crystals, thermal heads and the like, and to other photofabrication processes.